Continuous excavating and conveyor mechanism employing sonic energy

ABSTRACT

A combination excavator and conveyor which employs high-power sonic energy to loosen and fluidize the earthen material which is to be removed from the excavating area. Gyrating or orbital-mass sonic oscillators impart resonant standing waves to the earth cutting portion of the excavator as well as to the conveyor which carries the excavated material to a discharge location. Selfpropelled and towed versions are shown. Also illustrated is an integral excavating-conveying device in which the toothed end of a sonically excited conduit is used to &#39;&#39;&#39;&#39;nibble&#39;&#39;&#39;&#39; the earthen surface and thereafter fluidize and propel the loosened material through the sonically vibrated conduit to a discharge location.

United States Patent Albert G. Bodine 7877 Woodley Ave., Van Nuys,Calif. 91406 June 5, 1969 July 6, 1 971 Continuation of application Ser.No. 531,950, Mar. 4, 1966, now abandoned.

lnventor Appl. No. Filed Patented CONTINUOUS EXCAVATING AND CONVEYORMECHANISM EMPLOYING SONIC ENERGY 8 Claims, 23 Drawing Figs.

References Cited UNITED STATES PATENTS 8/1872 Johnson 37/19 X PrimaryExaminer-Robert E. Pulfrey Assistant Examiner-Clifford D. CrowderAtt0rney-Robert E. Geauque ABSTRACT: A combination excavator andconveyor which employs high-power sonic energy to loosen and fluidizethe earthen material which is to be removed from the excavating area.Gyrating or orbital-mass sonic oscillators impart resonant standingwaves to the earth cutting portion of the excavator as well as to theconveyor which carries the excavated material to a discharge location.Self-propelled and towed versions are shown. Also illustrated is anintegral excavating-conveying device in which the toothed end of asonically excited conduit is used to "nibble" the earthen surface andthereafter fluidize and propel the loosened material through thesonically vibrated conduit to a discharge location.

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fl/TOR/WSY CQNTllNiUtDlUfi EXCAVATHNG AND CflNi'lEYUHt MECHANISMlEMlPLGYlNG Stlthllltl lEhllElftGfl! This application is a continuationof application Ser. No. 531,950, filed Mar. 4, 1966, now abandoned.

This invention relates to excavating and conveyor mechanisms and, moreparticularly, to an improved excavating and conveyor mechanism employingsonic principles for loosening and fluidizing earthen material that isbeing removed from an excavating area. The conveyor mechanism embodyingthe invention is also adapted to operate in conjunction with dredgingapparatus, which is based on the application of one or more sonicprinciples, such as the apparatus disclosed in copending applicationSer. No. 413,495, filed Nov. 24, 1964, now U.S. Pat. No. 3,307,278.

inasmuch as the art relating to processing equipment and methods is notcoextensive with the art relating to acoustical engineering, and may beoutside the experience of those skilled in the former, and to aid in afull understanding of the invention, some general discussion anddefinitions are deemed to be useful. As used throughout thisspecification, sonic vibration means elastic vibrations, i.e., cyclicelastic deformations, which travel through a medium with acharacteristic velocity of propagation. If the vibrations travellongitudinally or create a longitudinal wave pattern in a medium orstructure having uniformly distributed constants of elasticity and mass,the vibrations are analogous to those of sound wave transmission.Regardless of the frequency of such elastic vibrations, the samemathematical formulas apply to them as to the study of sound wavetransmission.

In some elastic vibratory systems, the essential features of mass mayappear as a localized influence, referred to hereinafter as a lumpedconstant. A lumped constant in an elastically deformable medium providesan effect variously referred to as elasticity, modulus of elasticity,stiffness, stiffness modulus, or compliance (the reciprocal of stiffnessmodulus). These constants, when functioning in an elastically vibratorysystem, have cooperating and mutually influencing effects much likethose of equivalent factors in alternating current electrical systems.in fact, in both distributed and lumped constant systems, mass ismathematically equivalent to inductance; elastic compliance ismathematically equivalent to capacitance; and friction or other pureenergy dissipation is mathematically equivalent to resistance.

As was mentioned hereinbefore, because of these equivalents, the elasticvibratory systems of the apparatus of the present invention with theirmass stiffness and energy consumption, and their sonic energytransmission properties, can be viewed as equivalent electricalcircuits, where the functions can be expressed, considered, changed, andquantitatively analyzed by using well proven electrical formulas.

lt is important to recognize that the transmission of sonic energy intothe interface or work area between two parts to be moved against oneanother requires the aforementioned elastic vibration phenomena. inorder to attain the benefits of the present invention. There have beenother proposals involving exclusively simple bodily vibration of someparts; how ever, these simple bodily vibrations do not result in thebenefits of sonic or elastically vibratory action such as are inherentin the present invention.

Since sonic or elastic vibration results in the mass and elasticcompliance elements of the system taking on these spe cial propertiesakin to the parameters of inductance and capacitance in alternatingcurrent phenomena, vastly improved performance is attained in themechanical art. The concept of acoustic impedance becomes of paramountimportance in understanding such improved performance. Here, impedanceis the ratio of cyclic force or pressure acting in the media toresulting cyclic velocity of motion, just like the ratio of voltage tocurrent in electrical circuits. In this sonic adaptation, impedance isalso equal to the medium density times the speed of propagation of theelastic vibration. in this invention, impedance is important to theaccomplishment of desired ends, such as where there is an interface. Asonic vibration transmitted across an interface between two media or twostructures can experience some reflection, depending upon thedifferences of impedance of the media. This can cause large relativemotion, if desired, at the interface. impedance is also important toconsider if optimized energization of a system is desired. if theimpedances are adjusted to be somewhat matched, energy transmission ismade very effective.

Sonic energy of fairly high frequencies can have energy effects onmolecular or crystalline systems. Also, these fairly high frequenciescan result in very high periodic acceleration values, typically of theorder of hundreds or thousands of times the acceleration of gravity.This is because, from a mathematical point of view, acceleration varieswith the square of frequency. Accordingly, by taking advantage of thissquare function, very high forces can be produced by the sonic system ofthe present invention.

The present invention applies the foregoing sonic principles to anexcavating and conveyor mechanism for loosening and fluidizing earthenmaterial to vastly improve its ease of removal from an area to beexcavated. A longitudinal standing Wave is set up in the excavatingportion of the mechanism to loosen material to be removed. The loosenedmaterial is transferred automatically under the influence of sonicenergy to the conveyor portion of the mechanism, which may also havestanding waves set up therein to propel or aid in propelling theloosened material to its point of discharge.

in one embodiment of the invention, the conveyor portion may comprise anendless belt having flights thereon, which belt is arranged to bepositioned in conjunction with the excavation portion, so that theaction of the latter causes loosened material to be scooped or funneledonto the flights of the conveyor belt. The conveyor itself plays no partin the heavy work of digging or fragmentation, and hence may be arelatively light-duty carrier. it is pointed out that such anarrangement provides fast digging action and continuous flow of loosenedmaterial.

ln other embodiments of the invention, the conveyor portion may comprisea conduit such as an open trough or a closed pipe. When a conduit isused, a continuous sonic wave is maintained in the conduit, to causefluidization of material flowing through the conduit. The material beingconveyed may be dry or semidry and no liquid is required to cause thematerial to flow through the conduit.

it is believed that, in the case of a conduit, the conduit system itselfcompletely satisfies the requirements of capacitance and inductance thatare required for the operation of a sonic circuit. Therefore, since thematerial being moved does not function in a major way as a reactiveimpedance, it is possible for the material to function primarily as aresistive impedance. Thus, the individual grains of the material vibratein random directions with various amplitudes of vibration, vibraterelative to each other, and become very mobile. The result is that thematerial attains great fluidity, which prevents sticking or piling up ofthe material as it flows through the conduit. lln addition, by certainorientations of the sonic vibrations, it is possible to cause theconduit to pump the material along, and even to propel it along anuphill grade.

it is particularly pointed out that sonic energy is used to fluidizeearthen material from the instant that it is removed from the ground andon through the conduit system to its discharge point. The sonic energydelivered by the excavating portion of the apparatus causes fluidizationof the material in the earth, so that it is easily picked up andintroduced into the conduit system. Introduction of the material intothe conduit can be aided by locating a lip or blade section of thesonicallyactivated excavating portion of the apparatus so that it tendsto cause the material to flow into the conduit.

In another embodiment of the invention, a flow of air is introduced intothe conduit so as to further aid the introduction of fluidized materialinto the conduit and its flow through the conduit. Such a system isarranged so that the flowing material is delivered to a separating stagesuch as a centrifugal separator or cyclone" pump. In that stage, thedirt is thrown out of the air stream so that it can be discharged at thedelivery point and the air is discharged free of dust. Generally, theairstream is passed through a filter, and it may be desirable to applysonic energy to the filter so that any dust collected thereby iscontinually dropped off into the dirt-discharge region of the mechanism.

An important feature of the mechanism herein disclosed is that it movesfine particles very quickly away from the region of earth contact. Thisreduces absorption of sonic energy by these fine particles in the regionof excavation, where their cushioning effect could absorb a considerableamount of the energy needed for the excavation action. Thus, the quickremoval and flowing away of such fine material greatly reduces theconsumption of sonic energy. This feature, which is unique to thepresent invention, is not present in prior known earth-moving devices,where fine material is carried along with coarse material as a largebody, which is conducted or forced into a hopper or bowl-type structureor is pushed aside by a bulldozer blade. Thus, the excavating portion ofthe mechanism is constantly operating only in the tough, coarse materialthat remains after the fine material is removed. The excavating portionis able to apply its maximum fatigue and fracturing effect on the largerhard lumps which remain in the excavation region.

Further features and advantages of the invention will become apparentfrom the following description of several embodiments thereof, taken inconjunction with the accompanying drawings in which:

FIG. 1 is an elevational view of one embodiment of the in ventionshowing the mechanism in its retracted or nonexcavating position;

FIG. 2 is a plan view of the embodiment shown in FIG. I;

FIG. 3 is an elevational view of a portion of the mechanism shown inFIG. I in its extended or excavating position;

FIG. 4 is a partial end view of the mechanism of FIG. 3 taken on theline H of FIG. 3;

FIG. 5 is a cross-sectional view ofa mass oscillator that may be used inthe practice of the invention;

FIG. 6 is a perspective view, partially broken away, of another form ofoscillator that may be used in the practice of the invention;

FIG. 7 is a longitudinal cross-sectional view of the oscillator shown inFIG. 6;

FIG. 8 is a cross-sectional view of another form of mass oscillator;

FIG. 9 is a diagram of an equivalent electrical circuit analogous to thevibratory system shown in FIGS. ll-d;

' FIG. 10 is an elevational view of a modified form of the apparatusshown in FIG. 1;

FIG. 11 is a plan view of the mechanism shown in FIG. It);

FIG. 12 is an elevational view of another embodiment of the inventionemploying a different type of conveyor than that shown in FIGS. 1-4 andshowing the mechanism in its retracted position;

FIG. 13 is a plan view of the modification shown in FIG. I12;

FIG. 14 is an elevational view of the mechanism shown in FIG. 12, butshowing the mechanism in its extended position;

FIG. I5 is a sectional view taken on the line 15-15 of FIG. 14;

FIG. 16 is a sectional view taken on the line 16-16 of FIG. 14;

FIG. 17 is an end view, partially in section, taken on the line I7-l7 ofFIG. 14;

FIG. I8 is a diagrammatic view showing a different standing wave patternthat can be set up in the excavating portion of the mechanism shown inFIGS. 12-17;

FIG. I9 is a perspective view, partially broken away, of anotherembodiment of the conveyor portion of a mechanism embodying theinvention;

FIG. is an enlarged sectional view ofa portion of the conveyor shown inFIG. 19;

til

FIG. 211 is an elevational view of another modification of the Imechanism embodying the invention;

FIG. 22 is a sectional view taken on the line 22-22 of FIG. M; and

FIG. 23 is a longitudinal sectional, fragmentary view of the mechanismshown in FIG. 221.

FIGS. 1l,2,3 and 4 illustrate one embodiment of an excavating andconveyor mechanism embodying the invention, with FIGS. II and 2 showingthe mechanism in a retracted or nondigging position, and H65. 3 and 4showing the mechanism in an extended or digging position.

The mechanism of the invention is shown in FIG. I as being mounted on aself-powered tractor 3i) or other similar device. Although certainconventional elements have been omitted for ease in understanding thedrawings, it is to be understood that the vehicle 3t) contains not onlyits own motive power, but also contains means for generating hydraulicpower and electrical power to actuate the excavating and conveyingmechanism of the invention.

The apparatus of the invention comprises a pair of sonic resonating bars32, only one of which is shown in FIGS. I. and 3, and an endlessconveyor belt 34 arranged to follow a generally triangular path. Theentire mechanism is supported by a generally triangularly shaped framestructure 35 which is mounted on the vehicle 3 0. The resonating bars 32and the conveyor belt 34 are adapted to be raised and lowered withrespect to the frame structure, as wiil be hereinafter described indetail. The frame structure 36 comprises two similar halves, and theresonating bars 32 and the conveyor belt 34, along with their associatedsupporting parts, are mounted between the two halves of the framestructure as.

It is pointed out that the two similar haives of the frame structure 3&,and the various actuating mechanisms and lever arms to be hereinafterdescribed, are in general provided in pairs, one of each pair beingmounted adjacent each part of the frame structure Although the mechanismembodying the invention will be described hereinafter as incorporatingtwo resonating bars 32, it is apparent that any number of resonatingbars may be employed, depending upon the desired width of a cut of earthto be taken by the mechanism.

Each of the sonic resonating bars 32 is supported at its nodal points bya guide bar Each of the guide bars 33 is supported within a channelmember 4t) having an open side adjacent the resonating bars 32. Eachchannei member dil also has an open side opposite the resonating bar 32so that the guide bar 333 may be moved up and down within the channelmember it). The channel members so are secured to the frame structure 36as by being welded thereto. In turn, the frame structure 36 is fixedlymounted on the vehicle as shown at 42 and 4-4.

Vertical movement of the guide bars 38 and resonating bars 32 iscontrolled by actuation of a pair of hydraulic cylinders 46, each havinga movable piston rod Each hydraulic cylinder 46 is pivotally secured tothe frame structure 356, as at 50, and the outer ends of the piston rods48 are similarly secured to one arm of each of a pair of bellcranks '52,as at 54. The fulcrum of each bellcrank 52 is pivotaily mounted on theframe structure 34, as at 56.

The arm of each bellcrank 52 to which a piston rod 48 is secured ispivotally attached at its outer end to a link 58. The end of each link58 that is not attached to a bellcrank 52 is pivotally secured between apair of lips 33a extending outwardly from each guide bar 38 at its upperend.

Each sonic resonating bar 32 is provided at its lower end with a cuttertoe 32a in the shape of a pointed laterally extending projection. Eachof the resonating bars 32 also carries in its midsection a sonicvibration oscillator or generator 6th, each vibration generator 64)being powered by an electric motor 62. Each vibration generator so setsup a lateral standing wave in its associated resonating bar 32, each ofwhich is secured to the guide bar at its nodal points 64 and 66. Inorder to lower each resonating bars 32. so that its toe 32a engagesearth to be excavated, hydraulic pressure is removed from the associatedhydraulic cylinder 46 so that the piston rod 48 moves downwardly. Thiscauses the bellcranks 52 to rotate in a clockwise direction about thepivot points 56, thus causing the links 58 to move downwardly. As thelinks 53 move downwardly, they lower the guide bars 38 and theresonating bars 32, as shown in H6. 3. As previously mentioned, veryhigh periodic acceleration values result from the setting up of lateralstanding waves in the resonating bars 32. These high forces produced bythe sonic system of the invention result in the toes 32a of theresonating bars 32 fluidizing the earthen material, including rock, withwhich they come in contact. Thus, earthen material is rapidly andefficiently loosened from its surroundings and converted into a fluidstate, whereby it may easily be picked up and transported by a conveyor.

The conveyor portion of the mechanism of the invention is an integralpart thereof, and is linked to and interacts with the excavation portionof the mechanism, as will be hereinafter described. The conveyor belt 34is supported by three pulleys 68, 70 and 72 arranged in generallytriangular form. The pulley 68 is rotatably mounted between the twohalves of the frame structure 36, and is connected by means of a shaft74 and a conventional gear box 76 to a motor 76 for driving the conveyorbelt 34. The pulley 70 is rotatably mounted between the ends of twobellcranks 80, which are pivotally mounted on the same axis 69 as is thepulley 63. The third pulley 72 is rotatably mounted between the twosides of a scoop 82, which is secured to the resonating bars 32 at theirnodal points 66. The scoop 82 serves as a dual function of affording atie between the resonating bars 32 and the bottom turn of the conveyorbelt 34 around the pulley 72, and providing, by means of an inclinedfloor 62a, a path over which fluidized and sonically energized earthenmaterial passes in going from the areas of intensive fluidizationcreated by the resonating bars 32 to the conveyor belt 34.

The conveyor belt 34 is provided with a plurality of lands 34a which arein close proximity to the curved floor 820 of the scoop 82 and pick upthe fluidized material between the lands as the conveyor belt 34advances.

Coordination of two movement of the resonating bars 32 and their guidebars 3% and the conveyor portion of the mechanism is accomplished bymeans of the bellcranks 52, the bellcranks 80 and links 8 3 that linktogether the two short sharp arms of the bellcranks 52 and 36. As thebellcranks 52 rotate in a clockwise direction to lower the resonatingbars 32 into the earth, they cause the bellcranks 80 to rotate about theaxis 69 to simultaneously lower the conveyor portion of the mechanisminto the earth in synchronism with the movement of the resonating bars32. Thus, the pulley 7b follows a fanlike arcuate path as indicated bythe arrows 86 in H6. 3. The scoop 82 is also secured to the resonatingbars 32 at their nodal point 66 by means of arms d8 that preventrotational movement of the scoop about the point 66. Thus, movement ofthe resonating bars 32 and positions of the conveyor belt 34 aresynchronized so that the scoop 82 is always adjacent the rear end of thetoe 32a of each resonating bar 32.

As previously mentioned, the pulley 68 over which the conveyor belt 34passes is fixed in position relative to the frame structure 36. Thus, itprovides a convenient place for discharge of earthen materialtransported by the conveyor belt. As shown in FIGS. l and 2, in oneembodiment of the invention, the earthen materials may be dischargedinto a conventional bottom-drop hopper 92. The hopper 92 is providedwith a drop-bottom 94 which is opened and closed by means of a hydrauliccylinder 96. The hopper 92 is secured to the frame structure 36 as at98, and is maintained in position by an arm 100 secured at one end tothe hopper 92 and at the other end to the frame structure 36. Theadvantage of using a hopper is that one complete hopper load can bedischarged into a waiting dump truck 102 without tieup resulting frommaneuvering successive damp trucks into position beneath the hopper.

There are shown in F165. 3- two examples of sonic oscillators which maybe employed in the apparatus of ROS. ld. The operating principle of agyratory type sonic oscillator is shown in H6. 5 and comprises, in part,an outer cylinder and a smaller diameter inner cylinder llll2. The innercylinder H2 is provided with a plurality ofjet orifices or turbinenozzles lid. By applying fluid under pressure to the interior of thecylinder 11?. and withdrawing it from the interior of the cylinderllllti, the (outer) cylinder Hill, which acts as an orbiting mass, willbe caused to follow an epicyclic or gyratory path as it moves about theexterior surface of the (inner) cylinder H2. This will generate asubstantially sine wave vibration which will be imparted to thestructure supporting the outer cylinder M0.

There is shown in FIGS. 6 and 7 an alternative construction of a sonicoscillator of the orbiting mass type in which rotary kinetic energy,rather than hydraulic fluid pressure, is employed to drive the eccentricmass.

As shown, the orbiting mass oscillator comprises an outer cylinder M6which may be press-fitted into, or otherwise supported by, a frame llilbor other structure to which sonic energy is to be imparted. The cylinderM6 is closed at one end by a plate and a gear ring R22 and at the otherend by a frustoconical shell llZd and a gear ring 126. The plate 120 isprovided with a circularly grooved! track 1123. A stationary tube 113%is secured to the shell 112% and extends therefrom. The orbiting masscomprises a cylindrical weight E32 coaxially mounted on a gear member113 i for rotation therewith. A boss 136 extends from the gear member1134, and mates with or engages the circular track 128 in the plate 12b.The teeth of the gear member T34 mesh with the teeth of the gear ring1122. The opposite end of a stem 138, which runs through the cylindricalweight T32, is secured to a gear wheel Mi], the peripheral gear teeth ofwhich mesh with the interior gear teeth of the gear ring 126. The gearwheel BMW is provided with a frustoconical boss M2, which travels in amating circular groove TM in a drive member ll ib. A drive shaft li t-8is driven from a rotary prime mover (not shown). A splined end 114311 ofthe drive shaft M3 engages an interior mating spline of the drive member1146, which is rotatably supported by conventional ball bearings 15b andE52. Rotary motion is imparted to the drive member M6 which in turncauses the gear wheel M0 to rotate by toothed engagement therewith. Thisin turn will impart motion to the cylindrical weight 132 or orbitingmass causing it to revolve and follow an orbital path about the interiorsurface of the outer cylinder It to. I

A valuable feature of the sonic circuit of the present invention is theprovision of an extra elastic compliance reactance so that the inherentmass or inertia of various necessary bodies in the system does not causethe system to depart so far from resonance that a large proportion ofthe driving force is dis sipatcd in vibrating this mass. For example, inany practical construction, the mechanical osciilator or vibrationgenerator will require a body or supporting structure for carrying thecyclic force generating means. This supporting structure, even whenminimal, will have some finite mass or inertia. This inertia could be aforce-wasting detriment, acting as a blocking impedance, using up partof the periodic force output just to accelerate and decelerate thesupporting structure. However, by use of elastically vibratory structurein the system, the effect of this mass, or the mass reactance resultingtherefrom, is counteracted at the frequency for resonance and, when areso nant acoustic circuit is thus used, with adequate capacitance(elastic compliance reactance), these blocking impedances are tuned out,at resonance, and the periodic force generating means can thus deliverits full impulse to the work which is a resistive component of theimpedance.

FIG. 13 shows a modified vibration generator that may be used inpracticing the invention. The generator embodies a frame or body partuse, which has a cylindrical portion M2, formed with parallel end facesRM and a central bore ins. Wider bores 168 are formed at the ends of thebore 166. End plates T76 and 172 mate with the: end faces F.6d, and arefastened thereto by means of machine screws T74. The end plate 570projects into the adjacent counterbore i168, and is formed with a radiusabout a center point C located on the longitudinal axis A-A of thegenerator. This surface forms a bearing for the opposed convex endsurface of an inertia rotor, to be hereinafter described. The inertiarotor is shown generally by the numeral 178.

The opposite end plate 372 also has a portion projecting inwardly intothe adjacent counterbore 1168, and is formed on its inner side with astationary bevelring gear i555).

Tightly mounted inside the bore 166 is a hardened race ring or bearing1182, having a tapered bore forming a conical bearing surface 184, theprojected taper of which has its apex at C.

The conical inertia rotor 17? is comprised of a truncated conical rollerE86 rotatably mounted on a bearing sleeve 1238, the sides of which,projected, converge to the aforementioned center point C. The conicalroller T36 is of a smaller central angle than the tapered or conicalbearing surface 118 5, as shown in the drawing, so as to be capable oftravel in an orbital path as it rolls around the tapered bearing surfaceK84. The large end of the conical roller 18d has a convex bearingsurface 192, centered about point C, which bears against the con cavebearing surface 176.

The bearing sleeve T88, on which the conical roller T86 is rotatablymounted, projects axially from a bevel planet gear 194 positionedadjacent the small end of the roller 11%, and which meshes with theaforementioned bevel ring gear lift). The pitch cone" of the bevel geari9 3 conforms to or coincides with the cone defined by the roller 186.The angles of the bevel gears 184) and 1W4 also converge to the centerpoint C. it will be understood that bevel planet gear R94 rolls aroundthe bevel ring gear 184) in proper mesh therewith, as the conicalinertia roller 1% rolls around the conical bearing face 118 5, with theroller H86 gaining traction on the surface 1 as the generator comes upto speed and operation stabilizes. The roller i186 turns to anynecessary degree relative to the gear 194 as the generator initiallycomes up to running speed, or because of minor differences in the ratesof rotation of the gear T941 and the roller we produced by slippagebetween the ring gear 180 and conical bearing surface H84.

Projecting axially from the bevel gear T94- is an axial extension 196,which is provided with a splined connection 1953 to a conically gyratorytubular drive shaft 2%).

The roller R86 is held in assembly with the gear llWl by means of aspindle 202, which extends axially through tubular bearing sleeve 188and freely through a bore 261% in the large end portion of the roller186, the bore 24% being counterbored, as at 2&6, to receive an annularflange 20525 on the spindle 202. The opposite end portion of the spindle2092 is threaded to receive a locknut 2MP, which engages a washer 212positioned adjacent the extremity of the tubular gear extension 196, thewasher 212, as here shown, engaging the ends of the splines in the driveshaft 200. Sufficient play is provided to prevent binding of the roller2186 on the spindle 2'02 or on the tubular bearing KS8.

Projecting axially from the spindle 24172, outside of the flange 208 isa guide pin 211d which projects into an annular groove 216 formed in thearcuate end face T76 of the end plate H70, concentric with axis A-A. ina manner analogous to the embodiment shown in lFlGS. -7, the roller 1186is thereby positioned closely adjacent to, or in substantial rollingcontact with, the conical raceway H5 3, and the gear 194 is at the sametime maintained in proper mesh with the gear 184}. When the vibrationgenerator is up to speed, centrifugal force urges the roller 186radially outward against the conical bearing surface 184, and relievesthe pressure of the pin 2114 on the adjacent sidewall of the groove 2%.At such times, the roller 1136 has been able. to gain substantiallynonskid traction with the bearing surface H84, and the gear 194 rolls inproper mesh with the gear 180, the roller i186 and the gear 194 thusdescribing orbital paths about the bearing surface 1184i and the gear150, respectively. During this action, a small relative rotation orcreep is permitted between the roller 186 and the gear 194, so

3.. as to relive the gear teeth of strain that might occur if the roller136 were fixed thereto and were to tend to roll on its raceway at aspeed slightly different from that of the gear 194.

The driven extremity of the tubular drive shaft 200 is formed witharcuate splines 218, which engage internal splines 220 in a couplingsleeve 222, thus affording a universal joint. The coupling sleeve 222has a tubular extension 224, of reduced diameter, which is supported byconventional bearings 22 6 mounted between spacers 22S and 230 without ahousing tube 232. The latter is flanged, as at 234, for engagement bythe assembly screws 1'74, and the spacer 230 is similarly flanged, as at236, fora corresponding purpose.

The coupling sleeve 222 may be driven in any suitable manner. As hereshown, a tubular drive shaft 238, understood to extend from any suitableprime mover, preferably incorporating a variable speed drive, not shown,has splines 24! drivingly engaging the splines 228 in the sleeve 222.

it will be understood from the foregoing description how the conicalinertia rotor i136 and the gear 194 follow an orbital path about theconical raceway 184- and the bevel gear when the tubular drive shaft MM)is provided, in effect, with a universal joint action at the point ofthe splined connection 2183M, such that the shaft 2MB gyrates through aconical angle as the roller H36 and the gear i194 traverse their orbitalpaths.

The centrifugal force exerted by the inertia roller 186 on the bearingmember 182 is transmitted to a supporting member or bar 242, which ispress-fitted into a correspondingly-shaped recess in the end plate 170.Used singly, such a generator as disclosed in FIG. 8 exerts a gyratoryforce of vibration on the member 242. Used in pairs, with synchronizedand phased drive, a linear alternating force may be generated andapplied to a load.

FIG. 9? diagrammatically illustrates an electrical circuit that isequivalent to the mechanical resonant arrangement on which the presentinvention is based. As shown, an alternating current signal generator244, which is equivalent to one of the sonic oscillators or vibrationgenerators previously described, provides signals to a conventional tankcircuit. A capacitor C is connected across the signal generator 24d, anda resistance R and an inductive impedance L are connected in seriesacross the signal generator 24 As previously mentioned, the capacitor Crepresents the elastic compliance of the vibratory system, theinductance L represents the mass of the system, and the resistance Rrepresents the energy dissipation of the system used in loosening andfluidizing earth.

As is well known, when the frequency of the output signal of thegenerator 244 is properly adjusted, the R-L-C- tank circuit will go intoresonance. This is the equivalent of setting up a longitudinal standingwave in one of the resonating bars 32, as shown at 33 in P16. 1. Aspreviously mentioned, each bar 32 is supported at nodal points by aguide bar 3%, and has an antinode at its lower or earth-engaging end,which vibrates at the frequency of the vibration or sonic generatoracting on the resonating bar.

FIGS. W and ill! illustrate a modified form of the invention which isvery similar to that form shown in FIGS. 1 through 4, except that achute is provided to discharge earthen material transported by theconveyor belt rather than a hopper as shown in the first embodiment.Furthermore, the excavating and conveyor mechanism is adapted to berotated about a vertical axis so that earthen material may be dispersedover a wide area by the aforementioned chute. It is understood that thevarious power generating means mentioned in connection with theembodiment shown in FlGS. l-4l are also provided in the embodiment shownin FllGS. ill and 11.!n the latter embodiment, certain parts which areshown in FIGS. it and 2 have been omitted for the sake of clarity. Theprovision of such parts will be readily understood by one skilled in theart. As shown in FIGS. ill and ll, the mechanism of the invention ismounted on a pair of posts 25% secured to the vehicle 30 on oppositesides thereof. The posts 256 are supported vertically by links 2551between them and the vehicle 30. The two posts (not shown), if desired.

Instead of a hopper as shown in previous embodiments, the embodimentshown in FIGS. 10 and 11 is provided with a chute 258, which isswingable between the positions shown in broken lines in FIG. 11 as themechanism pivots about the points 256. The chute 258 is mounted on thetwo halves of the frame structure 36 in a position to receive earthenmaterial at its upper end discharged from the conveyor belt 34. Thechute 258 may be raised and lowered by means of a hydraulic cylinder 260mounted between the chute and vertically and horizontally extending arms36'a and 36b, respectively, secured to the frame structure 36'.

Earthen material flowing down the chute 258 is maintained in a fluidizedstate by means of a vibration generator 262 which is driven by a motor264 and sets up either a lateral or a longitudinal standing wave alongthe chute 258. Thus, earthen material in a fluidized state flowscontinuously and evenly down the chute.

Of course, the excavating and conveyor portions of the mechanism of theinvention are supported and actuated in the same manner as in theembodiment illustrated in FIGS. l4. Therefore, that portion of themechanism shown in FIGS. l and 11 will not be described. Briefly,however, it is to be understood that the embodiment of the inventionshown in FIGS. and I1 is provided with resonating bars having cuttingtoes, which resonating bars are supported in guide bars as shown inFIGS. 1-4. The resonating bars, and the associated conveyor portion ofthe mechanism, are linked together in the same manner as previouslyshown and described, and are raised and lowered together betweenretracted and excavating positions. It is again noted that the principledifference between the embodiment shown in FIGS. I4 and that shown inFIGS. 10 and 11 is in the pivotal mounting, whereby fluidized materialmay be discharged from the chute 258 over a wide area, which may bequite useful in a cut-and-fill operation.

FIGS. 12-16 illustrate another embodiment of the invention whichembodies a different type of conveyor than that previously shown, andwhich is carried by a towed vehicle, indicated generally by the numeral270. The vehicle 270 comprises a conventional frame structure 272 onwhich are con ventionally mounted a pair of rear wheels 274. Theexcavator and conveying mechanism is carried by a pair of levers 276,which are pivotally connected to opposite sides of the frame structure272, as at 278. It is noted that the pivotal points 278 are not at theend of the frame structure 272 but are intermediate the wheels 274 andthe end of the frame structure. The levers 276 are connected together bycross bars 2760 (FIG. 16).

Pivotally connected to the end of the frame structure 272, as at 280, isa supporting structure, indicated generally by the numeral 282, whichcarries the excavating and conveyor mechanism. The supporting structure282 is provided with two depending arms 284 which are pivotallyconnected to the levers 276, as at 286. The arms 284 are slotted as at284a to allow some horizontal movement of the arms.

The supporting structure 282 is provided with a flat top portion 288,which supports two internal combustion engines 290 which drive twovibration generators 292 of the types illus trated in FIGS. 5- -8 anddescribed in the aforesaid applica tion Ser. No. 413,495. As previouslypointed out, two generators are used with synchronized drive to providea linear alternating force to the resonating tubes and cutter heads tobe hereinafter described. Power from the engines 290 is transmitted tothe vibration generators 292 through conventional clutches 294 havingactuating handles 296. The engines 290 are connected from the clutches294 to the vibration generat l tors 292 through drive shafts 298suitably mounted in conventional bearings 300. It is to be understood,as previously noted, that any number of vibration generators and cuttersmay be employed depending upon the width ofcut desired, and theinvention is in no way limited to any particular number of generatorsand resonating tubes.

The vibration generators 292 set up a standing wave, as shown by thecurve 302 in FIG. 14, in a resonating tube 304 having an antinode 306 ata cutter head 308, which is threaded onto the bottom of the resonatingtube 304. The cutter head is toothed to enable air to enter through thecutter head even when it is held tightly against the earth. Theresonating tube 304 has a Venturi tube 310 mounted within it andsubstantially coaxial therewith. The Venturi tube 3110 extends through alateral opening 304a in the side of the resonating tube 304 and into aninlet of a cyclone separator 312, which serves to separate fluidizedearthen material from the fluid air in which it is carried. Air isadmitted between resonating tube 304 and the Venturi tube 310 throughthe opening 3040, as well as through the cutter head 308. As is wellknown by those skilled in the art, a cyclone separator acts much in thesame manner as a centrifuge. In other words, heavier material drawn intothe separator is discharged through one exit while lighter material isdischarged through another exit. In the present case, the heaviermaterial, that is, fluidized earth, is discharged into an exit pipe 316,and lighter material (air) is discharged onto the earth through an exitnozzle 314. A filter may also be used, if desired, to insure thatearthen material is not discharged through the nozzle 31.4.

The pipe 314 is connected to the entrance opening of conventional pump318, secured to the structure 282, whose discharge pipe 320 dischargesthe air.

The tubes 304 and 310 are raised and lowered by means of the levers 276previously mentioned, which are pivotally secured to the supportingstructure 282 at 286. The levers 276, which form part of the structurefor supporting and raising and'lowering the excavating and conveyormechanism, are actuated by an hydraulic cylinder 326, one end of whichis secured to the supporting structure .282 and the other end of whichis pivotally secured to a crossbar 276a connecting the levers 276. Thehydraulic cylinder 326 has a piston rod 326a which, when extended,causes the mechanism to assume the position shown in FIG. 12. As thepiston rod 326a is extended, it causes the levers 276 to rotateclockwise about the points 278, which causes the points 278 to moveupwardly along with the entire mechanism carried by the supportingstructure 282. Conversely, as the hydraulic cylinder 326 is deenergized,as shown in FIG. M, the pivot point 2718 moves downwardly and theresonating tube 30 with its associated cutter head 308 and Venturi tube310 move downwardly into engagement with the earth.

The right end of the mechanism is supported by a horizontal platelikemember 324 having two oppositely disposed vertical arms 323. The levers276 are respectively pivotally connected to the arms 328, as are a pairof wheels 3330. The levers are connected at points 332, and the wheelsare connected at points 334. The frame structure 282 is also pivotallyconnected to the resonating tube 304 by means of links 336, connectedbetween points 338 and 360.

The platelike member 324 is provided with a pair of lugs 3240 that maybe secured to a towing vehicle, a portion of which is shown at 340. Themember 324 also has an aperture 324b through which the resonating tube304 extends. One or more rings of elastic material 342 surround theresonating tube 304 where it passes through the aperture 3241; so thatthe tube 304 will not be damaged by contact with the member 324 as thetube vibrates or the vibrations be damped.

As the h draulic cylinder 326 is actuated and its piston rod 326a isextinded, the right ends of the levers 276 exert pressure, throu h themember 324 and the wheels 330, against the earth and cause thesupporting structure 282 to rise, thus raising the excavating andconveying mechanism mounted thereon. Conversely, when the cylinder 326is deenergized,

the levers 276 move in a counterclockwise direction and cause thesupporting structure 282 to be lowered and the mechanism of theinvention to engage the earth, as shown in FIGS. 14 and 15.

It is pointed out that the resonating tube 304 is supported at a node,which corresponds to the pivot point 340, so that the longitudinalstanding wave 302 set up therein is not damped by the mounting means.

Inasmuch as the resonant frequency of the tube 304 changes as it isdriven into the ground, the tube is isolated from the supportingstructure by a vibration isolating mechanism 350 which is shown indetail in FIG. 17. The isolating mechanism 350 comprises a cup-shapedmember 352 which encircles the resonating tube 304. The member 352 iscontained within a collar 354, which forms a portion of the supportingstructure 282. The resonating tube 304 has pressfitted thereon aringlike member 356 having a circular resilient washer 358 or the likewhich engages the inner surface of the cup-shaped member 352. The member352 is also provided with a pair of grooves into which are fittedO-rings 360 that encircle and engage the resonating tube 304. A fitting362 isprovided whereby air may be injected from a line 364 into theinterior of the cup-shaped member 352 between the washer 358 and theO-rings 360.

When any plane cross section in a long, thin rod is displacedlongitudinally relative to adjacent planes, elastic restoring forcescaused by either compression or tension in the rod tend to restore theplane to its normal position. These forces result in the propogation oflongitudinal waves along the axis of the rod. The interference of twosuch waves traveling in opposite directions sets up a pattern ofstanding waves in the rod having certain discrete frequencies. Themagnitude of these natural frequencies depends upon the length andmaterial of the rod and upon the particular constraints existing at thetwo ends of the rod. Nodal positions having no longitudinaldisplacements are spaced at intervals along the length of the rod asdetermined by the fundamental frequency. Whenever a given rod isvibrating longitudinally, one of its natural modes may be supported orclamped at a nodal position without interferring with its particularmode of vibration. Since only a few modes of vibration, or in some casesonly one, will have a nodal position at a given location, a judiciouschoice of support position is necessary to reduce unwanted modes ofvibration. However, it is not practical to support the rod at a nodalposition since the natural frequency of the rod continuously changes asthe rod is driven into the earth. The frequency of the sonic driverwould have to be continuously changed as is required to maintain the rodvibrating at its natural frequency. Since the rod cannot practically besupported at a nodal point, it is convenient to support it at one end.

In the embodiment of the invention shown in FIG. 14, there are twoantinodes and one node as shown by the curve 302. In some instances, itmay be desirable to drive the resonating bar so that it has more thanone nodal point along its length. Such an arrangement is illustrateddiagrammatically in FIG. 18 where the curve 366 illustrates two nodesand two antinodes in the standing wave set up in the tube 304. Thisarrangement also permits the resonating tube 304' to be supported atmore than one point without decreasing its resonant properties.

FIGS. 19 and 2t) illustrate a conveyor mechanism that may be utilized inthe mechanism of the invention. The mechanism there illustratedcomprises, in effect, a sonic pump which may be used to propel fluidizedmaterial along a horizontal path or up a grade. Alternatively, theconveyor may be utilized to fluidize material so that the material willflow by simple gravity where the material is relatively light and theflow path is down grade.

The conveyor comprises a conduit such as a trough or pipe 400 having aplurality of ridges 402 on its inner lower surface. Standing waves, suchas are illustrated by the curve 404 are set up along the length of theconduit 400 by means of vibration generators 406 and 408. The generators406, 403 may be of the type described in U.S. Pat. No. 2,960,314 thatgenerate standing waves transversely with respect to the conduit 400, asshown by the curve 409. Of course, the invention is not limited to theuse of any particular number of vibration generators and the twogenerators 406 and 4&8 are shown only as being exemplary. The generator406 is driven by a motor 410 and is mounted in conventional mountingsunderneath the conduit 400 to transmit oscillatory motion to the conduitthrough its under side. The vibration generator 408, which is driven bya motor 412, is mounted on the top side of the conduit 400 and both itand the conduit may be supported by a pair of cables 4M.

If it is desired to propel the material through the conduit 404) fromright to left, as seen in FIGS. 19 and 20, the vibration generators 406and 408 are rotated in a direction so as to cause a counterclockwiseturbulent motion of the material to be propelled within the conduit. Theridges 402 on the inside surface of the conduit 400 aid in establishingthe gyratory motion of the particles within the conduit. Of course, ifthe direction of rotation of the generators 406 and 408 is reversed, thedirection of flow of fluidized earthen material within the conduit willalso be reversed.

FIGS. 2l-23 illustrate another embodiment of the invention in which theexcavating and conveying portions of the mechanism are combined in oneunit serving a dual purpose. The embodiment shown in those figures isparticularly adapted for "nibbling at a slanted surface, such as isshown in FIGS. 21 and 23 at 420. As shown, the embodiment comprises aresonating tube 422 provided with cutter teeth on its earthengaging openend. The other end of the resonating tube 422 is conventionally securedby means of a connecting hose 426 to a conduit that may be in turnconnected to a conveyor of the type shown in FIGS. 1-4 or to that shownin FIGS. l9 and 20.

The resonating tube 422 is supported by a cable 430 which engages aU-shaped bracket 432 conventionally secured to the tube 422 as bywelding. Vibration is imparted to the resonating tube 422 by a vibrationgenerator 434 of the type previously described with reference to FIGS.19 and 20 and described in US. Pat. No. 2,960,314. Longitudinal standingwaves, as illustrated by the curve 436, serve the dual purpose offluidizing the earth which the cutter teeth 424 engage and propellingthe fluidized material upwardly through the resonating tube 422. As inthe embodiment described with reference to FIGS. l9 and 20, theresonating tube 422 is provided with ridges 438 on its inner lowersurface.

The vibration generator 434 is driven by a motor 440 to which it isconnected by a shaft 442. The vibration generator imparts vibration tothe tube 422 through a mounting 444, as described in the last mentionedU.S. patent which may be welded to the tube 422 as at 445. As noted inthat patent, the vibration generator includes a tube 446, with the motor440, generator 41%, the mounting 4M, and the tube 446 being suspendedfrom cables M8. The motor 440 is also secured to the resonating tube 422by means of a bracket 450 which is welded, or otherwise secured, to thetube 322 as at 452. The motor 440 is conventionally mounted on thebracket 450 at the end opposite to that where the bracket is secured tothe tube 422.

The conveyor portion of the embodiment shown in FIGS. 21-23 operates inthe same manner as shown in FIGS. 19 and 20. That is, it operates as asonic pump which propels fluidized material along its length because ofthe gyratory motion set up therein by the action of the vibrationgenerator 434 cooperating with the ridges 438 provided within theresonating tube 422. Thus, material may be propelled up a slope throughthe tube 422 and into the conduit $28 for delivery to another conveyoror to an outlet.

What I claim is:

1. An earth excavating and conveyor mechanism comprising:

cutter means adapted to engage substantially dry earth to be fluidizedand excavated;

elastic resonator means acoustically coupled to said cutter means at anantinode of said resonator means;

sonic oscillator means acoustically coupled to said elastic resonatormeans whereby an alternating force is imparted to said resonator meansand to said cutter means for loosening earth engaged by said cuttermeans;

means for admitting ambient air through said cutter means to aidfluidization of the earth loosened by said cutter continuously operatedmeans for delivering a continuous flow of fluidized earth from saidcutter means to said conveying means.

3. The mechanism defined by claim 1, wherein said elastic resonatormeans comprises a tube.

4. The mechanism defined by claim 1, wherein said elastic resonatormeans comprises a first tube, and said conveying means comprises Venturitube positioned inside said first tube and connected to a cyclone pump.

5. An earth excavating and conveyor mechanism adapted to be mounted on avehicle and comprising:

a frame structure secured to said vehicle;

elastic resonator means supported from said frame structure;

cutter means acoustically coupled to said resonator means and adapted toengage substantially dry earth to be fluidized and excavated;

sonic oscillator means acoustically coupled to said resonator meanswhereby a resonant standing wave is imparted thereto and to said cuttermeans for loosening earth engaged by said cutter means;

means for admitting ambient air through said cutter means and thus causefluidization of the earth loosened by said cutter means;

a tubular conduit for conveying earth positioned adjacent said cuttermeans and continuously operated during operation of said oscillatormeans;

means connected to saidframe structure and to said resonator means formoving said resonator means upwardly and downwardly in synchronism withrespect to said vehicle; and

continuously operated means for maintaining said loosened earth in afluidized state while said loosened earth is continuously moving throughsaid conveying means.

6. The mechanism defined by claim 5, further including continuouslyoperated means for delivering a continuous flow of fluidized earth fromsaid cutter means to said conveying means.

7. The mechanism defined by claim 5 wherein said elastic resonator meanscomprises a rigid tube, the elasticity of which is sufficient to permita sonic standing wave to be propagated therein.

8. An earth excavating and conveyor mechanism comprismg:

cylindrical cutter means having an open end adapted to engagesubstantially dry earth to be fluidized and excavated;

elastic resonator means acoustically coupled to said cutter means at anantinode of said resonator means;

sonic oscillator means acoustically coupled to said elastic resonatormeans whereby an alternating force is imparted to said resonator meansand to said cutter means for loosening earth engaged by said cuttermeans;

means for admitting ambient air through said cutter means to aidfluidization of the earth loosened by said cutter means;

earth conveying means comprising a rigid tubular conduit positionedadjacent said cutter means; and

continuously operated means for maintaining said loosened earth in afluidized state while saiid loosened earth is continuously moving fromsaid cutter means to said conveying means.

1. An earth excavating and conveyor mechanism comprising: cutter meansadapted to engage substantially dry earth to be fluidized and excavated;elastic resonator means acoustically coupled to said cutter means at anantinode of said resonator means; sonic oscillator means acousticallycoupled to said elastic resonator means whereby an alternating force isimparted to said resonator means and to said cutter means for looseningearth engaged by said cutter means; means for admitting ambient airthrough said cutter means to aid fluidization of the earth loosened bysaid cutter means; a tubular conduit for conveying earth, positionedadjacent said cutter means and continuously operated during operation ofsaid oscillator means; and means for maintaining said loosened earth ina fluidized state while said loosened earth is continuously moving tosaid conveying means.
 2. The mechanism defined by claim 1, furtherincluding continuously operated means for delivering a continuous flowof fluidized earth from said cutter means to said conveying means. 3.The mechanism defined by claim 1, wherein said elastic resonator meanscomprises a tube.
 4. The mechanism defined by claim 1, wherein saidelastic resonator means comprises a first tube, and said conveying meanscomprises Venturi tube positioned inside said first tube and connectedto a cyclone pump.
 5. An earth excavating and conveyor mechanism adaptedto be mounted on a vehicle and comprising: a frame structure secured tosaid vehicle; elastic resonator means supported from said framestructure; cutter means acoustically coupled to said resonator means andadapted to engage substantially dry earth to be fluidized and excavated;sonic oscillator means acoustically coupled to said resonator meanswhereby a resonant standing wave is imparted thereto and to said cuttermeans for loosening earth engaged by said cutter means; means foradmitting ambient air through said cutter means and thus causefluidization of the earth loosened by said cutter means; a tubularconduit for conveying earth positioned adjacent said cutter means andcontinuously operated during operation of said oscillator means; meansconnected to said frame structure and to said resonator means for movingsaid resonator means upwardly and downwardly in synchronism with respectto said vehicle; and continuously operated means for maintaining saidloosened earth in a fluidized state while said loosened earth iscontinuously moving through said conveying means.
 6. The mechanismdefined by claim 5, further including continuously operated means fordelivering a continuous flow of fluidized earth from said cutter meansto said conveying means.
 7. The mechanism defined by claim 5, whereinsaid elastic resonator means comprises a rigid tube, the elasticity ofwhich is sufficient to permit a sonic standing wave to be propagatedtherein.
 8. An earth excavating and conveyor mechanism comprising:cylindrical cutter means having an open end adapted to engagesubstantially dry earth to be fluidized and excavated; elastic resonatormeans acoustically coupled to said cutter means at an antinode of saidresonator means; sonic oscillator means acoustically coupled to saidelastic resonator means whereby an alternating force is imparted to saidresonator means and to said cutter means for loosening earth engaged bysaid cutter means; means for admitting ambient air through said cuttermeans to aid fluidization of the earth loosened by said cutter means;earth conveying meanS comprising a rigid tubular conduit positionedadjacent said cutter means; and continuously operated means formaintaining said loosened earth in a fluidized state while said loosenedearth is continuously moving from said cutter means to said conveyingmeans.